Vapor chamber, cooling device, electronic device, wavelength conversion device, and projector

Abstract

To provide a vapor chamber, a cooling device, an electronic device, a wavelength conversion device, and a projector that can enhance pressure resistance and cooling performance.SOLUTION: A vapor chamber comprises: a first board having thermal conductivity; a second board opposed to the first board, and having thermal conductivity; a housing chamber comprising a housing space constituted in such a manner that a peripheral edge part of the first board and a peripheral edge part of the second board are joined; a working medium housed in the housing chamber, and to be changed into a gas phase and a liquid phase by heat; and a plurality of columns arranged between an inner surface of the first board and an inner surface of the second board in the housing chamber. The first board comprises: an arrangement region located in an outer surface of the first board, and on which a heat generating body is arranged; and a corresponding region located in the inner surface of the first board, and corresponding to the arrangement region. The plurality of columns include at least one inside column arranged on the corresponding region, and a plurality of outside columns arranged outside the corresponding region. The number of the inside columns per unit area on the corresponding region is larger than the number of the columns per unit area in the whole housing chamber.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a vapor chamber, a cooling device, an electronic device, a wavelength conversion device, and a projector. [Background technology]

[0002] BACKGROUND ART Conventionally, a cooling mechanism for cooling a light source unit including a plurality of light-emitting elements that emit light is known (see, for example, Patent Document 1). The cooling mechanism described in Patent Document 1 includes a heat receiving plate, a heat diffusion member, heat dissipation fins, and a cooling fan. A light source unit is fixed to the heat receiving plate. The heat diffusion member is a vapor chamber. The heat diffusion member is inserted into an opening in the heat receiving plate and has a protruding portion that contacts a base member that holds multiple light-emitting elements in the light source unit. The heat dissipation fins are fixed to the heat diffusion member, and airflow is circulated through the multiple fins of the heat dissipation fins by the cooling fan.

[0003] On the other hand, a vapor chamber having a plurality of pillars provided therein is known (see, for example, Patent Document 2). The vapor chamber described in Patent Document 2 includes a housing having an internal space formed by a first metal plate and a second metal plate joined together in an opposing state. The internal space contains a wick structure and a working medium, and also has a plurality of pillars disposed therein. The pillars protrude from the second metal plate toward the first metal plate. The pillars support the first metal plate by contacting the wick structure or by contacting the first metal plate through through holes provided in the wick structure. In the vapor chamber described in Patent Document 2, when an external force acts on the outer surface of the housing, the pillars suppress deformation of the housing and prevent the internal space from becoming narrower. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-128465 [Patent Document 2] Japanese Patent Publication No. 2022-63805 Summary of the Invention [Problem to be solved by the invention]

[0005] In the cooling mechanism described in Patent Document 1, the protruding portion of the heat diffusion member contacts the base member of the light source unit, which is the heat source. This results in low heat transfer efficiency from the base member to the heat diffusion member. To address this issue, it is conceivable to join the heat source and the vapor chamber together to efficiently transfer heat from the heat source to the vapor chamber. However, the high temperature generated when joining the heat source to the vapor chamber increases the internal pressure of the vapor chamber, causing an expansion force to act on the vapor chamber. To address this, it is possible to provide multiple pillars inside the vapor chamber, as in the vapor chamber described in Patent Document 2. However, in areas where the temperature becomes locally high, such as where a heat source is joined, the expansion force is likely to exceed the limit of the joint between the first and second substrates formed by the multiple pillars, causing the vapor chamber to easily expand. On the other hand, it is possible to increase the pressure resistance of the vapor chamber by increasing the number of pillars, but if the number of pillars installed is increased overall, the internal space will become narrower and it will become more difficult for the working medium to circulate, which will result in a decrease in the cooling performance of the vapor chamber. For these reasons, there has been a demand for a vapor chamber configuration that can improve pressure resistance and cooling performance. [Means for solving the problem]

[0006] A vapor chamber according to a first aspect of the present disclosure comprises a first substrate having thermal conductivity, a second substrate facing the first substrate and having thermal conductivity, a storage chamber having a storage space formed by joining the peripheral edge of the first substrate and the peripheral edge of the second substrate, a working medium stored in the storage chamber and changing between a gas phase and a liquid phase due to heat, and a plurality of pillars arranged between the inner surface of the first substrate and the inner surface of the second substrate in the storage chamber, wherein the first substrate has an arrangement area located on the outer surface of the first substrate where a heating element is arranged, and a corresponding area located on the inner surface of the first substrate corresponding to the arrangement area, and the plurality of pillars include at least one inner pillar arranged in the corresponding area and a plurality of outer pillars arranged outside the corresponding area, and the number of the inner pillars per unit area in the corresponding area is greater than the number of the pillars per unit area in the entire storage chamber.

[0007] A cooling device according to a second aspect of the present disclosure includes the vapor chamber according to the first aspect and the heat generating element joined to the placement area.

[0008] An electronic device according to a third aspect of the present disclosure includes the cooling device according to the second aspect.

[0009] A wavelength conversion device according to a fourth aspect of the present disclosure includes the cooling device according to the second aspect, wherein the heating element is a phosphor that converts the wavelength of incident light and emits fluorescent light, and the phosphor is bonded to the placement area via a thermally conductive bonding material.

[0010] A projector according to a fifth aspect of the present disclosure includes a light source, a wavelength conversion device according to the fourth aspect described above, into which light from the light source is incident as excitation light, an image forming device that forms image light from light including the fluorescent light emitted from the phosphor, and a projection optical device that projects the image light. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a projector according to a first embodiment. [Figure 2]FIG. 1 is a schematic diagram showing the configuration of a light source device according to a first embodiment. [Figure 3] FIG. 1 is a perspective view showing a wavelength converter according to a first embodiment. [Figure 4] FIG. 1 is an exploded perspective view showing a wavelength converter according to a first embodiment. [Figure 5] FIG. 2 is a diagram showing the internal structure of a vapor chamber in the first embodiment. [Figure 6] FIG. 3 is a diagram showing the vapor chamber with the second substrate removed in the first embodiment. [Figure 7] FIG. 4 is a cross-sectional view showing a first modified example of the vapor chamber in the first embodiment. [Figure 8] FIG. 10 is a cross-sectional view showing a second modified example of the vapor chamber in the first embodiment. [Figure 9] FIG. 10 is a diagram showing the internal structure of a vapor chamber of a wavelength conversion device provided in a projector according to a second embodiment. [Figure 10] FIG. 11 is a cross-sectional view showing a vapor chamber of a wavelength conversion device provided in a projector according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] [First embodiment] Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings. [Projector configuration] FIG. 1 is a schematic diagram showing the configuration of a projector 1 according to this embodiment. The projector 1 according to this embodiment is an electronic device that projects image light according to image information. As shown in Fig. 1, the projector 1 includes an exterior housing 11 and an image projection device 2 housed in the exterior housing 11. In addition, although not shown, the projector 1 also includes a control device that controls the operation of the projector 1 and a power supply device that supplies power to the electronic components of the projector 1.

[0013] [Configuration of image projection device] The image projection device 2 projects image light according to input image information. The image projection device 2 includes a light source device 3, a homogenizing optical system 21, a color separation optical system 22, a relay optical system 23, an image forming device 24, an optical component housing 25, and a projection optical device 26.

[0014] The light source device 3 emits illumination light to the homogenizing optical system 21. The configuration of the light source device 3 will be described in detail later. The homogenizing optical system 21 homogenizes the illumination light emitted from the light source device 3. The homogenized illumination light passes through a color separation optical system 22 and a relay optical system 23, and illuminates a modulation area of ​​a light modulation element 243 (described later). The homogenizing optical system 21 includes lens arrays 211 and 212, a polarization conversion element 213, and a superimposing lens 214. The color separation optical system 22 separates the illumination light incident from the homogenization optical system 21 into red, green, and blue color lights. The color separation optical system 22 includes dichroic mirrors 221 and 222, and a reflecting mirror 223 that reflects the blue light separated by the dichroic mirror 221.

[0015] The relay optical system 23 is provided on the optical path of the red light, which is longer than the optical paths of the other colored lights, to suppress loss of the red light. The relay optical system 23 includes an incident-side lens 231, a relay lens 233, and reflecting mirrors 232 and 234. In this embodiment, the red light is guided to the relay optical system 23. However, this is not limiting, and for example, the colored light having a longer optical path than the other colored lights may be blue light, and the blue light may be guided to the relay optical system 23.

[0016] The image forming device 24 modulates the red, green, and blue color lights emitted and separated from the light source device 3, and combines the modulated color lights to form image light. That is, the image forming device 24 forms image light from light including fluorescent light emitted from the phosphor 41 of the wavelength conversion device 4A that constitutes the light source device 3. The image forming device 24 has three field lenses 241, three incident-side polarizing plates 242, three light modulation elements 243, three exit-side polarizing plates 244, and one color combining optical system 245, which are provided according to the color lights incident thereon.

[0017] The light modulation elements 243 modulate the light from the light source device 3 to form image light. Specifically, the light modulation elements 243 modulate the color light incident from the incident-side polarizing plate 242 in accordance with an image signal, and emit the modulated color light. The three light modulation elements 243 include a light modulation element 243R that modulates red light, a light modulation element 243G that modulates green light, and a light modulation element 243B that modulates blue light. An example of the light modulation elements 243 is a transmissive liquid crystal panel.

[0018] The color combining optical system 245 combines the three color lights modulated by the light modulation elements 243R, 243G, and 243B and incident from each of the output-side polarizing plates 244. The image light combined by the color combining optical system 245 is incident on the projection optical device 26. In this embodiment, the color combining optical system 245 is formed by a substantially rectangular parallelepiped cross dichroic prism, but may also be formed by a plurality of dichroic mirrors.

[0019] The optical component housing 25 accommodates therein the above-described uniformizing optical system 21, color separation optical system 22, relay optical system 23, and image forming device 24. The image projection device 2 is designed to have an optical axis Ax, and the optical component housing 25 holds the uniformizing optical system 21, color separation optical system 22, relay optical system 23, and image forming device 24 at predetermined positions on the optical axis Ax. The light source device 3 and the projection optical device 26 are arranged at predetermined positions on the optical axis Ax. The projection optical device 26 projects the image light incident from the image forming device 24 onto a projection surface such as a screen. That is, the projection optical device 26 projects the image light formed by the image forming device 24. The projection optical device 26 can be, for example, a lens assembly including a plurality of lenses (not shown) and a lens barrel 261 that houses the plurality of lenses.

[0020] [Light source configuration] FIG. 2 is a schematic diagram showing the configuration of the light source device 3. As shown in FIG. The light source device 3 emits illumination light that illuminates the modulation region of each light modulation element 243 to the homogenizing optical system 21. As shown in Fig. 2, the light source device 3 includes a light source 31, a diffuse transmission section 32, a light separation section 33, a first light collecting element 34, a wavelength conversion device 4A, a second light collecting element 35, a diffuse reflection element 36, and a phase difference section 37, as well as a support member 38 that supports these elements.

[0021] The light source device 3 has illumination optical axes Ax1 and Ax2 that intersect with each other. The light source 31, the diffuse transmission section 32, the light separation section 33, the first light collecting element 34, and the wavelength conversion device 4A are arranged on an illumination optical axis Ax1. The light separating unit 33, the second light collecting element 35, the diffuse reflecting element 36, and the phase difference unit 37 are arranged on the illumination optical axis Ax2. The light separating unit 33 is arranged at the intersection of the illumination optical axis Ax1 and the illumination optical axis Ax2. The illumination optical axis Ax2 coincides with the optical axis Ax at the position of the lens array 211. In other words, the illumination optical axis Ax2 is set on an extension of the optical axis Ax.

[0022] The light source 31 includes a substrate 311 , a light emitting element 312 , a collimator lens 313 , and a heat dissipation member 314 . The substrate 311 supports a light emitting element 312 and a collimator lens 313 . The light emitting element 312 emits light. Although not shown, the light emitting element 312 is composed of a plurality of semiconductor lasers that emit blue light. The light emitting element 312 and the substrate 311 are one of the heating elements that generate heat when the light source 31 is turned on. The collimator lens 313 collimates the light emitted from the light emitting element 312 . The heat dissipation member 314 is connected to the surface of the substrate 311 opposite to the surface on which the light emitting element 312 and the collimator lens 313 are arranged in a heat-transferable manner. The heat dissipation member 314 is cooled by cooling gas sent from a fan (not shown), and thus the light source 31 is cooled.

[0023] The diffuse transmission section 32 diffuses the light incident from the light source 31 to make the illuminance distribution of the emitted light uniform. Examples of the diffuse transmission section 32 include a configuration having a hologram, a configuration in which a plurality of small lenses are arranged in a plane perpendicular to the optical axis, and a configuration in which the surface through which light passes is rough. It should be noted that a homogenizer optical element having a pair of multi-lens arrays may be used in the light source device 3 instead of the diffuse transmission section 32. On the other hand, when the diffuse transmission section 32 is used, the distance from the light source 31 to the light separation section 33 can be made shorter than when a homogenizer optical element is used. The light emitted from the diffuse transmission section 32 is incident on the light separation section 33.

[0024] The light separating unit 33 functions as a half mirror that transmits some of the light incident from the light source 31 via the diffuse transmission unit 32 and reflects the other light. The light separating unit 33 functions as a dichroic mirror that transmits the blue light incident from the diffuse reflection element 36 and reflects light that is incident from the wavelength conversion device 4A and has a wavelength longer than that of the blue light. In detail, the light separation section 33 transmits a first partial light, which is a portion of the blue light incident from the diffusion transmission section 32, and causes it to enter the first light-collecting element 34, and reflects the second partial light, which is the other blue light, and causes it to enter the second light-collecting element 35. In this embodiment, in consideration of light absorption in the wavelength conversion device 4A, the light separation unit 33 sets the amount of light of the first partial light to be greater than the amount of light of the second partial light. However, this is not limiting, and the amount of light of the first partial light may be the same as or smaller than the amount of light of the second partial light.

[0025] The first light collecting element 34 collects, onto the wavelength converter 4A, the first partial light that has passed through the light separating unit 33. The first light collecting element 34 also collimates the light incident from the wavelength converter 4A. In this embodiment, the first light collecting element 34 has two lenses 341 and 342, but the number of lenses that make up the first light collecting element 34 is not limited to two.

[0026] The wavelength converter 4A diffuses and emits light obtained by converting the wavelength of incident light in the opposite direction to the incident direction of the light into the wavelength converter 4A. More specifically, the wavelength converter 4A is excited by the incidence of blue light, which is excitation light, and diffuses and emits fluorescent light having a wavelength longer than the wavelength of the incident blue light toward the first light collecting element 34. That is, the wavelength converter 4A converts light having a first wavelength band emitted from the light source 31 into light having a second wavelength band different from the first wavelength band. The light emitted from the wavelength converter 4A is, for example, fluorescent light having a peak wavelength of 500 to 700 nm. The fluorescent light emitted from the wavelength conversion device 4A passes through the first light collecting element 34 along the illumination optical axis Ax1, and then enters the light separation unit 33. The fluorescent light that has entered the light separation unit 33 is reflected by the light separation unit 33 in a direction along the illumination optical axis Ax2, and enters the phase difference unit 37. The configuration of such a wavelength converter 4A will be described in detail later.

[0027] The second light collecting element 35 collects the second partial light reflected by the light separating section 33 and incident thereon onto the diffuse reflecting element 36. Furthermore, the second light collecting element 35 collimates the blue light incident thereon from the diffuse reflecting element 36. In this embodiment, the second light collecting element 35 has two lenses 351 and 352, similar to the first light collecting element 34, but the number of lenses constituting the second light collecting element 35 is not limited to two.

[0028] The diffuse reflecting element 36 has a substrate 361 and a diffuse reflecting layer 362 provided on the substrate 361 at a position facing the second light collecting element 35. The diffuse reflection layer 362 reflects and diffuses the blue light incident from the second light collecting element 35 at the same diffusion angle as the fluorescent light emitted from the wavelength conversion device 4A. In other words, the diffuse reflection layer 362 reflects and diffuses the incident light without converting the wavelength of the incident light. The blue light reflected by the diffuse reflection layer 362 passes through the second light collecting element 35, then passes through the light separation unit 33, and enters the phase difference unit 37. That is, the light entering the phase difference unit 37 from the light separation unit 33 is white light in which blue light and fluorescent light are mixed. The phase difference unit 37 converts the white light incident from the light separation unit 33 into light containing a mixture of s-polarized light and p-polarized light. The white illumination light converted in this manner enters the homogenizing optical system 21 described above.

[0029] [Configuration of wavelength conversion device] FIG. 3 is a perspective view showing the wavelength converter 4A as viewed from the excitation light incident side, and FIG. 4 is an exploded perspective view showing the wavelength converter 4A as viewed from the excitation light incident side. As shown in FIGS. 2 to 4, the wavelength converter 4A includes a phosphor 41, a bonding material 42, a heat dissipation member 43, a fixing member 44, and a vapor chamber 5A. In the following description, the three mutually orthogonal directions are referred to as the +X direction, +Y direction, and +Z direction. The direction opposite the +X direction is referred to as the -X direction, the direction opposite the +Y direction is referred to as the -Y direction, and the direction opposite the +Z direction is referred to as the -Z direction. In this embodiment, the +Z direction is the direction in which fluorescent light is emitted from the phosphor 41. That is, the excitation light emitted from the first light collecting element 34 travels in the -Z direction and enters the phosphor 41, and the phosphor 41 emits fluorescent light in the +Z direction.

[0030] The phosphor 41 is provided on the first outer surface 51A of the vapor chamber 5A. More specifically, the phosphor 41 is provided in an arrangement region 523 of a first surface 521 that constitutes the first outer surface 51A of a first substrate 52 that constitutes the vapor chamber 5A. The phosphor 41 includes phosphor particles, and blue light from the light source 31 is incident on the phosphor 41 in the -Z direction as excitation light via the first light collecting element 34, etc. The phosphor 41 emits fluorescent light, which is unpolarized light obtained by converting the wavelength of the incident blue light, in the +Z direction. The circle on the phosphor 41 shown in FIGS. 3 and 4 is a spot SP that indicates the position where the excitation light is incident. In this embodiment, the phosphor 41 is formed in a rectangular shape when viewed from the +Z direction, but may also be in a circular or other polygonal shape.

[0031] The bonding material 42 is a thermally conductive bonding material that bonds the first substrate 52 and the phosphor 41 of the vapor chamber 5A. The bonding material 42 is made of, for example, a silver paste containing silver nanoparticles, and functions as a reflective layer that reflects fluorescent light incident from the phosphor 41 toward the phosphor 41 after bonding the first substrate 52 and the phosphor 41. That is, the wavelength conversion device 4A has a reflective layer disposed between the phosphor 41 and the first substrate 52. Note that the reflective layer does not have to be made of the bonding material 42, and may be formed on the other surface of either the phosphor 41 or the first substrate 52 that faces the other. Alternatively, the surface of the first substrate 52 that faces the phosphor 41 may function as the reflective layer.

[0032] The heat dissipation member 43 is connected to the second outer surface 51B of the vapor chamber 5A in a heat-transferable manner, the second outer surface 51B being opposite to the first outer surface 51A on which the phosphor 41 is provided. The heat dissipation member 43 has a heat receiving plate 431 and a plurality of fins 432. The heat receiving plate 431 is connected to the second outer surface 51B via thermally conductive grease or the like so as to be capable of transferring heat therethrough, and receives heat radiated from the second outer surface 51B. Each of the multiple fins 432 extends from the heat receiving plate 431 to the side opposite the vapor chamber 5A. Each of the multiple fins 432 dissipates heat transferred from the heat receiving plate 431. A cooling gas is circulated through the multiple fins 432 by a fan (not shown), thereby cooling the heat dissipation member 43 and, ultimately, the phosphor 41. The fixing member 44 fixes the heat dissipation member 43 to the vapor chamber 5A. More specifically, the fixing member 44 is inserted into the vapor chamber 5A through the heat receiving plate 431, thereby fixing the heat dissipation member 43 to the vapor chamber 5A in a heat transferable manner. In this embodiment, the wavelength conversion device 4A has two fixing members 44, but the number of fixing members 44 can be changed as appropriate.

[0033] [Vapor chamber configuration] The vapor chamber 5A supports the phosphor 41 and dissipates heat transferred from the phosphor 41 via the bonding material 42 to the heat dissipation member 43, thereby cooling the phosphor 41. The vapor chamber 5A, together with the phosphor 41 and the bonding material 42, constitutes a cooling device CDA. In other words, the projector 1, which is an electronic device, is equipped with a cooling device CDA that includes the phosphor 41, which is a heat-generating element, the bonding material 42, and the vapor chamber 5A.

[0034] Fig. 5 is a diagram showing the internal structure of the vapor chamber 5A. Specifically, Fig. 5 is a diagram showing a cross section of the vapor chamber 5A along the XZ plane as viewed from the -Y direction. As shown in Figures 3 to 5, the vapor chamber 5A has a first outer surface 51A, a second outer surface 51B, a first substrate 52, and a second substrate 53, and also has a storage chamber 54, a capillary force structure 55A, and a plurality of pillars 6A, as shown in Figure 5. The first outer surface 51A is an outer surface facing the +Z direction in the vapor chamber 5A. The second outer surface 51B is an outer surface facing the −Z direction in the vapor chamber 5A. In this manner, the first outer surface 51A and the second outer surface 51B are surfaces facing opposite directions in the vapor chamber 5A.

[0035] [Configuration of the first board] The first substrate 52 is a flat substrate made of a metal with good thermal conductivity, such as copper. That is, the first substrate 52 has thermal conductivity. As shown in FIG. 5 , the first substrate 52 is positioned in the +Z direction relative to the second substrate 53, and is combined with the second substrate 53 to form an accommodation chamber 54. The first substrate 52 has a first surface 521, a second surface 522, an arrangement region 523, a first peripheral portion 524, a first inner surface 525, and a corresponding region 526.

[0036] The first surface 521 is a surface of the first substrate 52 facing the +Z direction, and constitutes the first outer surface 51A. An arrangement area 523 is provided on the first surface 521. That is, the arrangement area 523 is located on the first outer surface 51A. The arrangement region 523 is a region where the above-described phosphor 41 and bonding material 42 are arranged. More specifically, the arrangement region 523 is a region on the first surface 521 that overlaps with the phosphor 41 and the bonding material 42 when viewed from the +Z direction. For example, if the area of ​​the bonding material 42 is equal to or larger than the area of ​​the phosphor 41, the arrangement region 523 is a region that overlaps with the phosphor 41 when viewed from the +Z direction. Furthermore, for example, if the area of ​​the bonding material 42 is smaller than the area of ​​the phosphor 41, the arrangement region 523 is a region that overlaps with the bonding material 42 when viewed from the +Z direction.

[0037] The second surface 522 is the surface of the first substrate 52 facing the −Z direction. The first peripheral edge portion 524 is a peripheral portion of the second surface 522. The first peripheral edge portion 524 is bonded to a second peripheral edge portion 533 of the second substrate 53, which will be described later. The first inner surface 525 is the inner surface of the first peripheral edge portion 524 of the second surface 522, and constitutes the inner surface on the first substrate 52 side in the accommodation space 54S of the accommodation chamber 54. A first capillary force structure 56A of the capillary force structure 55A, which will be described later, is provided on the first inner surface 525. The corresponding region 526 is a region on the first inner surface 525 that overlaps with the placement region 523 when viewed from the −Z direction. In other words, the corresponding region 526 is a region on the first inner surface 525 that corresponds to the placement region 523.

[0038] [Configuration of the second board] The second substrate 53 is a concave substrate made of the same material as the first substrate 52. That is, the second substrate 53 has thermal conductivity. The overall thickness of the second substrate 53 is greater than the overall thickness of the first substrate 52. The second substrate 53 is located in the -Z direction relative to the first substrate 52 and is combined with the first substrate 52 to form the accommodation chamber 54. The second substrate 53 has a first surface 531, a second surface 532, a second peripheral portion 533, and a second inner surface 534.

[0039] The first surface 531 is the surface of the second substrate 53 facing the +Z direction. The second peripheral edge portion 533 is a portion that protrudes in the +Z direction from the peripheral edge portion of the first surface 531. The first peripheral edge portion 524 and the second peripheral edge portion 533 are joined together to form the vapor chamber 5A. The second inner surface 534 is the inner surface of the second peripheral edge portion 533 on the first surface 531, and constitutes the inner surface on the second substrate 53 side in the accommodation space 54S of the accommodation chamber 54. A second capillary force structure 57A (described later) of the capillary force structure 55A is provided on the second inner surface 534. The second surface 532 is a surface of the second substrate 53 facing the +Z direction, and constitutes the second outer surface 51B. That is, the heat receiving plate 431 of the heat dissipation member 43 is connected to the second surface 532 so as to be able to transfer heat.

[0040] [Configuration of the containment chamber and working medium] The accommodation chamber 54 has an accommodation space 54S formed between the first substrate 52 and the second substrate 53 by joining the first peripheral portion 524 and the second peripheral portion 533. The accommodation space 54S accommodates the capillary force structure 55A and the plurality of pillars 6A, as well as a working medium that changes between a liquid phase and a gas phase due to heat. That is, the vapor chamber 5A has a working medium accommodated in the accommodation chamber 54. The working medium is, for example, water, and is sealed in the accommodation chamber 54 in a decompressed state. The working medium changes phase from liquid to gas due to heat, diffuses within the accommodation chamber 54, and is condensed to change phase from gas to liquid. For example, the liquid-phase working medium is vaporized by heat transferred from a heating element disposed in the arrangement region 523 and diffuses within the accommodation chamber 54. The gas-phase working medium diffused within the accommodation chamber 54 is condensed into a liquid-phase working medium by transferring heat to, for example, the second inner surface 534. The liquid-phase working medium is held in a capillary force structure 55A (described later) and transported by capillary force to a position within the accommodation chamber 54 where the working medium is likely to vaporize. An example of the position where the working medium is likely to vaporize is a corresponding region 526 corresponding to the arrangement region 523 where the heating element, the phosphor 41, is disposed.

[0041] [Capillary force structure] The capillary force structure 55A holds the working medium in a liquid phase. The capillary force structure 55A transports the working medium in a liquid phase to a position close to the phosphor 41, which is a heating element, by capillary force. As shown in Fig. 5, the capillary force structure 55A includes a first capillary force structure 56A, a second capillary force structure 57A, and a third capillary force structure 58, and each of the capillary force structures 56A, 57A, and 58 is formed of, for example, a wick or a mesh.

[0042] The first capillary force structure 56A is provided on the first inner surface 525 and joined to the first inner surface 525. In this embodiment, the first capillary force structure 56A has holes 56A1 through which pillars 6A, which will be described later, are inserted. The second capillary force structure 57A is provided on the second inner surface 534 and joined to the second inner surface 534. In this embodiment, the second capillary force structure 57A has holes 57A1 through which pillars 6A, which will be described later, are inserted. The third capillary force structure 58 is provided on the outer peripheral surface of a pillar 6A (described later). The third capillary force structure 58 connects the first capillary force structure 56A and the second capillary force structure 57A so that the working medium in a liquid phase can move from the second capillary force structure 57A to the first capillary force structure 56A via the third capillary force structure 58.

[0043] [Column Configuration] The multiple pillars 6A are disposed between the first inner surface 525 and the second inner surface 534 that form the storage space 54S of the storage chamber 54. In this embodiment, one end of each of the multiple pillars 6A is inserted through a hole 56A1 of the first capillary force structure 56A in the +Z direction and joined to the first inner surface 525, and the other end of each of the multiple pillars 6A is inserted through a hole 57A1 of the second capillary force structure 57A in the -Z direction and joined to the second inner surface 534. The multiple pillars 6A connect the first inner surface 525 and the second inner surface 534 and function to maintain the shape of the vapor chamber 5A. For example, the multiple pillars 6A suppress expansion of the vapor chamber 5A and also suppress inward deformation of the vapor chamber 5A when an external force is applied.

[0044] FIG. 6 is a view of the vapor chamber 5A from which the second substrate 53 has been removed, as viewed from the -Z direction. As shown in FIG. 6, the plurality of pillars 6A includes a plurality of inner pillars 61 and a plurality of outer pillars 64. The multiple outer pillars 64 are arranged outside the corresponding region 526 in the accommodation chamber 54. The multiple outer pillars 64 are arranged at approximately equal intervals in the +X direction and the +Y direction in the accommodation chamber 54.

[0045] The multiple inner pillars 61 are arranged in the corresponding regions 526 in the accommodation chamber 54. More specifically, each of the multiple inner pillars 61 is arranged so that at least a portion of it is located within the corresponding region 526 in the accommodation chamber 54. The multiple inner pillars 61 include at least one of the regional pillars 62 and the peripheral pillars 63. In this embodiment, the multiple inner pillars 61 include each of the regional pillars 62 and the peripheral pillars 63.

[0046] The intra-area pillars 62 are inner pillars that are entirely disposed within the corresponding area 526 when viewed from the second substrate 53 side relative to the first substrate 52. In other words, the entire intra-area pillars 62 are disposed inside the corresponding area 526 when viewed from the -Z direction. The peripheral pillars 63 are inner pillars arranged on the periphery of the corresponding region 526. That is, the peripheral pillars 63 are arranged across the inside and outside of the corresponding region 526. In this embodiment, a plurality of peripheral pillars 63 are provided in the corresponding region 526, and the plurality of peripheral pillars 63 are arranged at equal intervals along the periphery of the corresponding region 526. In this embodiment, the periphery of the corresponding region 526 corresponds to the periphery of the arrangement region 523 in which the phosphor 41 and the bonding material 42 are arranged, as shown by the dotted line in FIG. 6 , when viewed from the +Z direction. That is, the periphery of the corresponding region 526 corresponds to the periphery formed by at least one of the periphery of the phosphor 41 and the periphery of the bonding material 42, when viewed from the +Z direction.

[0047] Here, the number of inner columns 61 per unit area in the corresponding region 526 is greater than the number of columns 6A per unit area in the entire storage chamber 54. That is, the number of inner columns 61 per unit area in the corresponding region 526 is greater than the number of columns 6A, including the inner columns 61 and outer columns 64, per unit area in the entire storage chamber 54. In the example of FIG. 6, the number of inner columns 61 arranged in the corresponding region 526 is five, and the number of columns 6A in the entire storage chamber 54 is 33. The multiple columns 6A arranged in this manner suppress deformation of the vapor chamber 5A. In particular, deformation of the vapor chamber 5A in the corresponding region 526 is suppressed. In this embodiment, each of the inner pillar 61 and the outer pillar 64 is formed in a cylindrical shape when viewed from the ±Z direction. That is, each of the regional inner pillar 62, the peripheral pillar 63, and the outer pillar 64 is formed in a cylindrical shape when viewed from the ±Z direction. However, this is not limited to this, and at least one of the pillars 62 to 64 may be formed in a rectangular pillar shape. Furthermore, at least one of the pillars 62 to 64 may be formed in a shape such that the cross-sectional area along the XY plane decreases toward the center in the +Z direction and increases from the center in the +Z direction toward the +Z direction and the -Z direction.

[0048] [Effects of the first embodiment] The projector 1 according to the present embodiment described above has the following advantages. A projector 1, which is an electronic device, is provided with a cooling device CDA. The cooling device CDA includes a vapor chamber 5A and a phosphor 41 bonded to the placement area 523 of the vapor chamber 5A. The phosphor 41 corresponds to a heating element.

[0049] The vapor chamber 5A includes a first substrate 52, a second substrate 53, a storage chamber 54, a working medium, and a plurality of pillars 6A. The first substrate 52 and the second substrate 53 each have thermal conductivity. The second substrate 53 faces the first substrate 52 in the +Z direction. The accommodation chamber 54 has an accommodation space 54S formed by joining the first peripheral edge portion 524 of the first substrate 52 and the second peripheral edge portion 533 of the second substrate 53 together. The working medium is contained in the containing chamber 54 and changes between a gas phase and a liquid phase due to heat. The multiple pillars 6A are arranged in the accommodation chamber 54 between the first inner surface 525 and a second inner surface 534 which is the inner surface of the second substrate 53. The first inner surface 525 is the inner surface of the first substrate 52, and is the inner surface of the accommodation chamber 54 which is formed by the first substrate 52 and faces the second substrate 53. The second inner surface 534 is the inner surface of the second substrate 53 which is formed by the second substrate 53 and faces the first substrate 52.

[0050] The first substrate 52 has an arrangement area 523 and a corresponding area 526 . The arrangement region 523 is located on the first surface 521 that constitutes the first outer surface 51A of the vapor chamber 5A. That is, the arrangement region 523 is located on the outer surface of the first substrate 52. In the arrangement region 523, a phosphor 41 that is a heat generating element is arranged. The corresponding area 526 is located on the first inner surface 525 and corresponds to the placement area 523 . The plurality of pillars 6A includes at least one inner pillar 61 and a plurality of outer pillars 64. The inner pillars 61 are disposed in the corresponding regions 526 . The outer posts 64 are disposed outside the corresponding regions 526 . The number of inner columns 61 per unit area in the corresponding region 526 is greater than the number of columns 6A per unit area in the entire storage chamber 54.

[0051] With this configuration of the vapor chamber 5A, the number of inner pillars 61 per unit area in the corresponding region 526 is greater than the number of pillars 6A per unit area in the entire accommodation chamber 54. This increases the pressure resistance of the vapor chamber 5A against expansion in the corresponding region 526. This makes it possible to suppress expansion of the vapor chamber 5A even when a thermal load is applied to the arrangement region 523 from the outside. On the other hand, the number of outer pillars 64 per unit area arranged outside the corresponding region 526 is smaller than the number of inner pillars 61 per unit area arranged in the corresponding region 526, so that the working fluid that has changed from a liquid phase to a gas phase due to heat transferred from the phosphor 41, which is a heating element, in the corresponding region 526 located on the first inner surface 525 can be more easily diffused outside the corresponding region 526. Therefore, expansion and deformation of the vapor chamber 5A can be suppressed while maintaining the diffusibility of the working medium in the vapor chamber 5A. As a result, the cooling device CDA equipped with the vapor chamber 5A can be a cooling device that can suppress expansion of the vapor chamber 5A while cooling the phosphor 41. Furthermore, by being equipped with the cooling device CDA, the projector 1, which is an electronic device, can be a projector that can operate stably.

[0052] The projector 1 also includes a light source 31, a wavelength conversion device 4A into which light from the light source 31 is incident as excitation light, an image forming device 24, and a projection optical device . The image forming device 24 forms image light from light including fluorescent light emitted from the phosphor 41 of the wavelength conversion device 4 A. The projection optical device 26 projects the image light. The wavelength conversion device 4A includes the cooling device CDA. The heating element arranged in the arrangement region 523 of the first substrate 52 constituting the vapor chamber 5A of the cooling device CDA is a phosphor 41 that converts the wavelength of incident light and emits fluorescent light. The phosphor 41 is bonded to the arrangement region 523 via a thermally conductive bonding material 42. According to such a configuration, the phosphor 41 can be stably cooled, so that a wavelength conversion device 4A capable of stably emitting fluorescent light can be configured, and in turn, a projector 1 that can operate stably can be configured.

[0053] In the vapor chamber 5A, the inner pillars 61 include intra-region pillars 62. The entire intra-region pillars 62 are disposed within the corresponding region 526 when viewed from the second substrate 53 side relative to the first substrate 52. According to this configuration, the intra-area pillars 62, which are entirely disposed within the corresponding area 526, can suppress expansion of the portion of the vapor chamber 5A corresponding to the arrangement area 523. Therefore, the pressure resistance strength of the vapor chamber 5A can be increased.

[0054] In the vapor chamber 5A, the inner pillars 61 include peripheral pillars 63 arranged on the periphery of the corresponding region 526. The peripheral pillars 63 are arranged across the interior and exterior of the corresponding region 526. According to this configuration, the peripheral columns 63 can prevent the peripheral portion of the placement area 523 from expanding due to heat acting on the placement area 523 from the outside. This can increase the pressure resistance strength of the vapor chamber 5A.

[0055] In the vapor chamber 5A, a plurality of peripheral columns 63 are provided at equal intervals around the periphery of the corresponding region 526. The plurality of outer columns 64 are arranged at equal intervals. That is, of the plurality of outer columns 64, the plurality of outer columns 64 arranged around the inner column 61 are arranged at equal intervals. According to this configuration, the peripheral columns 63 are provided at equal intervals around the periphery of the corresponding area 526, thereby effectively suppressing expansion of the portion of the vapor chamber 5A corresponding to the placement area 523. Therefore, the flatness of the vapor chamber 5A can be reduced. Furthermore, since the multiple outer columns 64 arranged around the inner column 61 are arranged at equal intervals, the multiple outer columns 64 can be prevented from hindering the diffusion of the working medium vaporized in the corresponding region 526 outside the corresponding region 526.

[0056] The vapor chamber 5A is disposed on the first inner surface 525 inside the accommodation chamber 54 and includes a first capillary force structure 56A that holds the working medium in a liquid phase. This configuration makes it easier to supply the liquid-phase working medium to the corresponding region to which heat from the heating element is transferred, thereby improving the efficiency of heat transfer from the heating element to the working medium and the cooling efficiency of the heating element.

[0057] In the vapor chamber 5A, the inner column 61 is joined to the first inner surface 525, avoiding the first capillary force structure 56A. That is, the first capillary force structure 56A has a hole 56A1, and the inner column 61 is joined to the first inner surface 525, passing through the hole 56A1. According to this configuration, the inner pillar 61 can be directly joined to the first inner surface 525. Therefore, the joining strength between the inner pillar 61 and the first inner surface 525 can be increased, and the pressure resistance strength of the vapor chamber 5A can be further increased.

[0058] The vapor chamber 5A includes a second capillary force structure 57A and a third capillary force structure 58. The second capillary force structure 57A is disposed on the second inner surface 534 inside the accommodation chamber 54 and holds the working medium in a liquid phase. The third capillary force structure 58 is provided on the outer surface of each pillar 6A and connects the first capillary force structure 56A and the second capillary force structure 57A. For example, the third capillary force structure 58 is provided on the outer surface of the inner pillar 61 and connects the first capillary force structure 56A and the second capillary force structure 57A. According to this configuration, the liquid-phase working medium transported by the second capillary force structure 57A can be supplied to the first capillary force structure 56A via the third capillary force structure 58, which in turn makes it easier to supply the liquid-phase working medium to the corresponding region 526. Therefore, it is possible to further improve the efficiency of heat transfer from the phosphor 41, which is a heat-generating body, to the liquid-phase working medium, and to improve the cooling efficiency of the phosphor 41.

[0059] [Modification of the first embodiment] In the vapor chamber 5A, one end of each pillar 6A is joined to the first inner surface 525 through the hole 56A1 of the first capillary force structure 56A, and the other end of each pillar 6A is joined to the second inner surface 534 through the hole 57A1 of the second capillary force structure 57A. However, the joining state between the plurality of pillars 6A and the first substrate 52 and the second substrate 53 is not limited to the above.

[0060] [First Modification of the First Embodiment] FIG. 7 is a diagram showing a part of a cross section along the XZ plane of a vapor chamber 5B which is a first modified example of the vapor chamber 5A. 7 has the same configuration and function as the vapor chamber 5A described above, except that it has a capillary force structure 55B instead of the capillary force structure 55A. The capillary force structure 55B has a first capillary force structure 56B and a second capillary force structure 57B instead of the first capillary force structure 56A and the second capillary force structure 57A, and also has a third capillary force structure 58, and functions in the same way as the capillary force structure 55A.

[0061] The first capillary force structure 56B is bonded to the first inner surface 525, and the second capillary force structure 57B is bonded to the second inner surface 534. Here, the first capillary force structure 56B does not have a hole 56A1, and the second capillary force structure 57B does not have a hole 57A1. Therefore, one end of the pillar 6A, which is the end in the +Z direction, is bonded to the surface of the first capillary force structure 56B facing the -Z direction, and the other end of the pillar 6A, which is the end in the -Z direction, is bonded to the surface of the second capillary force structure 57B facing the +Z direction. In the example of FIG. 7 , one end of the inner pillar 61 is bonded to the first inner surface 525 via the first capillary force structure 56B, and the other end of the inner pillar 61 is bonded to the second inner surface 534 via the second capillary force structure 57B.

[0062] Such a vapor chamber 5B exhibits the same effects as the vapor chamber 5A, and also exhibits the following effects. In the vapor chamber 5B, at least one inner pillar 61 is bonded to a first inner surface 525, which is the inner surface of the first substrate 52, via a first capillary force structure 56B. With this configuration, the inner pillars 61 can prevent the area of ​​the first capillary force structure 56B from decreasing, thereby preventing a decrease in the holding and transporting power of the liquid-phase working medium by the first capillary force structure 56B. Therefore, the liquid-phase working medium can be efficiently transported to the corresponding region 526, thereby increasing the efficiency of heat transfer from the phosphor 41, which is a heating element, to the liquid-phase working medium.

[0063] [Second Modification of the First Embodiment] FIG. 8 is a diagram showing a part of a cross section along the XZ plane of a vapor chamber 5C which is a second modified example of the vapor chamber 5A. Furthermore, one of the first capillary force structures 56A and 56B may be combined with one of the second capillary force structures 57A and 57B. 8 has the same configuration and function as the vapor chamber 5A described above, except that it has a capillary force structure 55C instead of the capillary force structure 55A. The capillary force structure 55C has a first capillary force structure 56A, a second capillary force structure 57B, and a third capillary force structure 58, and functions in the same way as the capillary force structure 55A. In the vapor chamber 5C, one end of each pillar 6A is inserted through a hole 56A1 of the first capillary force structure 56A and bonded to the first inner surface 525, and the other end of the pillar 6A is bonded to a surface of the second capillary force structure 57B facing the +Z direction. For example, one end of each pillar 6A is bonded to the first inner surface 525, avoiding the first capillary force structure 56A, and the other end of each pillar 6A is bonded to the second inner surface 534 via the second capillary force structure 57B. In the example of Fig. 8, one end of the inner pillar 61 is bonded to the first inner surface 525, avoiding the first capillary force structure 56A, and the other end of the inner pillar 61 is bonded to the second inner surface 534 via the second capillary force structure 57B.

[0064] Such a vapor chamber 5C exhibits the same effects as the vapor chamber 5A, and also exhibits the following effects. The vapor chamber 5C is disposed on the second inner surface 534 inside the accommodation chamber 54 and includes a second capillary force structure 57B that holds the working medium in a liquid phase. One end of the inner pillar 61 is joined to the first inner surface 525, avoiding the first capillary force structure 56A, and the other end of the inner pillar 61 is joined to the second inner surface 534 via the second capillary force structure 57B. The first inner surface 525 corresponds to the inner surface of the first substrate 52, and the second inner surface 534 corresponds to the inner surface of the second substrate 53.

[0065] According to this configuration, one end of the inner pillar 61 can be directly joined to the first inner surface 525. Therefore, the joining strength between the inner pillar 61 and the first inner surface 525 can be increased. Furthermore, since the inner pillars 61 can prevent the area of ​​the second capillary force structure 57B from decreasing, the retention and transport force of the liquid phase working medium by the second capillary force structure 57B can be prevented from decreasing. Therefore, the pressure resistance strength of the vapor chamber 5C can be further increased, and the liquid phase working medium can be efficiently transported toward the corresponding area 526, thereby improving the heat transfer efficiency from the phosphor 41, which is a heating element, to the liquid phase working medium.

[0066] [Second embodiment] Next, a second embodiment of the present disclosure will be described. The projector according to this embodiment has a similar configuration to the projector 1 according to the first embodiment, but the cross-sectional area of ​​the pillars arranged inside the accommodation chamber of the vapor chamber is different. Note that in the following explanation, parts that are the same or approximately the same as parts already explained will be assigned the same reference numerals and explanations thereof will be omitted.

[0067] [Schematic configuration of projector and wavelength conversion device] Fig. 9 is a diagram showing the internal structure of the vapor chamber 5D of the wavelength conversion device 4D included in the projector according to this embodiment. Specifically, Fig. 9 is a diagram showing the vapor chamber 5D from which the second substrate 53 has been removed, as viewed from the -Z direction. The projector according to this embodiment has the same configuration and functions as the projector 1 according to the first embodiment, except that it has a wavelength conversion device 4D shown in FIG. 9 instead of the wavelength conversion device 4A. The wavelength conversion device 4D has the same configuration and functions as the wavelength conversion device 4A according to the first embodiment, except that it has a vapor chamber 5D instead of the vapor chamber 5A. That is, the wavelength conversion device 4D according to this embodiment has a cooling device CDD instead of the cooling device CDA, and also has a heat dissipation member 43. The cooling device CDD has the same configuration and function as the cooling device CDA according to the first embodiment, except that it has a vapor chamber 5D instead of the vapor chamber 5A. That is, the cooling device CDD according to this embodiment has a phosphor 41, a bonding material 42, and a vapor chamber 5D, and functions in the same way as the cooling device CDA.

[0068] [Vapor chamber configuration] The vapor chamber 5D has the same configuration and function as the vapor chamber 5A, except that it includes multiple pillars 6D instead of the multiple pillars 6A. That is, the vapor chamber 5D includes a first outer surface 51A, a second outer surface 51B, a first substrate 52, a second substrate 53, a storage chamber 54, a capillary force structure 55A, and multiple pillars 6D. Note that the vapor chamber 5D may include a capillary force structure 55B or a capillary force structure 55C instead of the capillary force structure 55A.

[0069] [Multiple column configuration] The multiple pillars 6D include multiple inner pillars 65 instead of the multiple inner pillars 61, and also include multiple outer pillars 64, and have the same functions as the multiple pillars 6A according to the first embodiment. The multiple inner pillars 65, like the multiple inner pillars 61, are provided in the corresponding region 526 of the first substrate 52. More specifically, each of the multiple inner pillars 65 is arranged so that at least a portion thereof is located within the corresponding region 526 in the accommodation chamber 54. The +Z direction end of each of the multiple inner pillars 65 is directly bonded to the corresponding region 526 on the first inner surface 525, avoiding the first capillary force structure 56A, or is bonded to the corresponding region 526 via the first capillary force structure 56B. Although not shown, the -Z direction end of each of the multiple inner pillars 65 is directly bonded to the second inner surface 534, avoiding the second capillary force structure 57A, or is bonded to the second inner surface 534 via the second capillary force structure 57B.

[0070] The positions of the inner pillars 65 in the corresponding region 526 are the same as the positions of the inner pillars 61 in the corresponding region 526 shown in the first embodiment. That is, the multiple inner pillars 65 include at least one of the inner pillars 66 arranged in the same position as the inner pillars 62, and the peripheral pillars 67 arranged in the same position as the peripheral pillars 63. In this embodiment, the multiple inner pillars 65 include both the inner pillars 66 and the peripheral pillars 67.

[0071] The cross-sectional area of ​​the portion of the inner post 65 facing the first substrate 52, taken along the first inner surface 525, is smaller than the cross-sectional area of ​​the portion of the outer post 64 facing the first substrate 52, taken along the first inner surface 525. In other words, the cross-sectional area of ​​the portion of the intra-regional post 66 facing the first substrate 52, taken along the first inner surface 525, is smaller than the cross-sectional area of ​​the portion of the outer post 64 facing the first substrate 52, taken along the first inner surface 525. In addition, the cross-sectional area of ​​the portion of the peripheral post 67 facing the first substrate 52, taken along the first inner surface 525, is smaller than the cross-sectional area of ​​the portion of the outer post 64 facing the first substrate 52, taken along the first inner surface 525. In other words, the cross-sectional area of ​​each inner pillar 65 perpendicular to the central axis of each inner pillar 65 is smaller than the cross-sectional area of ​​each outer pillar 64 perpendicular to the central axis of each outer pillar 64. Although not shown in the figure, the cross-sectional area of ​​the inner column 65 along the second inner surface 534 at the end on the second substrate 53 side is smaller than the cross-sectional area of ​​the outer column 64 along the second inner surface 534 at the end on the second substrate 53 side.

[0072] As described above, the arrangement of the inner columns 65 in the corresponding region 526 is the same as the arrangement of the inner columns 61 in the corresponding region 526 for the vapor chamber 5A. Furthermore, the arrangement of the outer columns 64 in the storage chamber 54 is the same as the arrangement of the outer columns 64 in the storage chamber 54 for the vapor chamber 5A. Therefore, the number of inner columns 65 per unit area in the corresponding region 526 is greater than the number of columns 6D, including the inner columns 65 and outer columns 64, per unit area in the entire storage chamber 54. On the other hand, since the cross-sectional area of ​​the inner pillar 65 is smaller than the cross-sectional area of ​​the outer pillar 64, it is possible to reduce the area occupied by the inner pillar 65 in the corresponding region 526 where the working fluid changes from liquid to gas. This makes it easier to change the working fluid from liquid to gas in the corresponding region 526, and also makes it easier to diffuse the working fluid that has changed from liquid to gas in the corresponding region 526 to the outside of the corresponding region 526, and ultimately throughout the entire accommodation chamber 54.

[0073] [Effects of the second embodiment] The projector according to this embodiment described above has the same effects as the projector 1 according to the first embodiment, and also has the following effects. In the vapor chamber 5D, the cross-sectional area of ​​the inner column 65 along the first inner surface 525 at the portion on the first substrate 52 side is smaller than the cross-sectional area of ​​each outer column 64 along the first inner surface 525 at the portion on the first substrate 52 side. With this configuration, the area of ​​the portion in the corresponding region 526 where the liquid-phase working medium is changed into the gas-phase working medium by the heat transferred from the phosphor 41, which is a heating element, can be prevented from being reduced by the inner column 65, thereby preventing the heat transfer from the first inner surface 525 to the liquid-phase working medium from being hindered. Therefore, it is possible to prevent a decrease in the efficiency of heat transfer from the phosphor 41 to the liquid-phase working medium.

[0074] [Third embodiment] Next, a third embodiment of the present disclosure will be described. The projector according to this embodiment has a similar configuration to the projector 1 according to the first embodiment, but differs in that the arrangement area in the vapor chamber where the heat generating element is arranged is configured by a recess provided in the first substrate. Note that in the following explanation, parts that are the same or approximately the same as parts already explained will be assigned the same reference numerals and explanations thereof will be omitted.

[0075] [Schematic configuration of projector and wavelength conversion device] FIG. 10 is a diagram showing a cross section along the XZ plane of a vapor chamber 5E of a wavelength conversion device 4E provided in a projector according to this embodiment. The projector according to this embodiment has the same configuration and functions as the projector 1 according to the first embodiment, except that it has a wavelength conversion device 4E shown in FIG. 10 instead of the wavelength conversion device 4A. The wavelength conversion device 4E has the same configuration and functions as the wavelength conversion device 4A according to the first embodiment, except that it has a vapor chamber 5E instead of the vapor chamber 5A. That is, the wavelength conversion device 4E according to this embodiment has a cooling device CDE instead of the cooling device CDA, and also has a heat dissipation member 43 not shown in FIG. The cooling device CDE according to this embodiment includes a phosphor 41, a bonding material 42, and a vapor chamber 5E, and functions in the same manner as the cooling device CDA.

[0076] [Vapor chamber configuration] The vapor chamber 5E has the same configuration as the vapor chamber 5D according to the second embodiment, except that it has a first substrate 52E instead of the first substrate 52. That is, the vapor chamber 5E has a first outer surface 51A, a second outer surface 51B, a first substrate 52E, a second substrate 53, a storage chamber 54, a capillary force structure 55A, and a plurality of pillars 6D. Note that the vapor chamber 5E may have a capillary force structure 55B or a capillary force structure 55C instead of the capillary force structure 55A.

[0077] [Configuration of the first board] Like the first substrate 52 according to the first embodiment, the first substrate 52E has thermal conductivity and is combined with a second substrate 53 positioned in the -Z direction relative to the first substrate 52E to form an accommodation chamber 54. The first substrate 52E has a first surface 521, a second surface 522, an arrangement region 523, a first peripheral portion 524, a first inner surface 525, and a corresponding region 526, and further has an arrangement recess 527. The arrangement recess 527 is a recess recessed in the -Z direction, which is toward the second substrate 53, from the first surface 521. A bonding material 42 is arranged on a bottom surface 5271 of the arrangement recess 527 facing the +Z direction, and thereby the phosphor 41 is arranged on the bottom surface 5271. That is, in this embodiment, the arrangement region 523 is located on the bottom surface of the arrangement recess 527.

[0078] For this reason, the thickness dimension of the first substrate 52E in the placement region 523 is smaller than the thickness dimension of the first substrate 52E around the placement region 523. In this embodiment, the dimension in the +Z direction of the bottom surface 5271 of the placement recess 527 is 0.15 mm or more and 0.60 mm or less, whereas the dimension in the +Z direction of the first substrate 52E is 0.80 mm or more and 2.00 mm or less. In other words, the thickness dimension of the first substrate 52E in the placement region 523 is 0.15 mm or more and 0.60 mm or less, whereas the thickness dimension of the first substrate 52E around the periphery of the placement region 523 is 0.80 mm or more and 2.00 mm or less.

[0079] [Effects of the third embodiment] The projector according to this embodiment described above has the same effects as the projector according to the second embodiment, and also has the following effects. In the vapor chamber 5E, the thickness dimension of the first substrate 52E in the placement region 523 is smaller than the thickness dimension of the first substrate 52E around the placement region 523. This configuration can improve the efficiency of heat transfer from phosphor 41, which is a heat-generating body, to first inner surface 525 of first substrate 52E, and further improve the efficiency of heat transfer from phosphor 41 to the liquid-phase working medium. Therefore, heat from phosphor 41 can be efficiently transferred to the liquid-phase working medium, and the cooling efficiency of phosphor 41 can be improved.

[0080] [Modification of the embodiment] The present disclosure is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present disclosure are included in the present disclosure. In the above embodiments, the inner pillars 61, 65, at least a portion of which is arranged in the corresponding region 526 corresponding to the arrangement region 523, include the intra-region pillars 62, 66, and the intra-region pillars 62, 66 are arranged entirely within the corresponding region 526 when viewed from the second substrate 53 side relative to the first substrates 52, 52E. However, this is not limiting, and the intra-region pillars 62, 66 may be omitted if the number of inner pillars 61, 65 per unit area in the corresponding region 526 is greater than the number of pillars 6A, 6D per unit area in the entire accommodation chamber 54. Meanwhile, in each of the above embodiments, one in-area pillar 62, 66 is provided in the corresponding area 526. However, this is not limiting, and a plurality of in-area pillars 62, 66 may be provided in the corresponding area 526.

[0081] In each of the above embodiments, the inner pillars 61, 65, at least a portion of which is arranged in the corresponding region 526 corresponding to the arrangement region 523, include a plurality of peripheral pillars 63, and the peripheral pillars 63 are arranged across the inside and outside of the corresponding region 526. However, this is not limiting, and as long as the number of inner pillars 61, 65 per unit area in the corresponding region 526 is greater than the number of pillars 6A, 6D per unit area in the entire storage chamber 54, the peripheral pillars 63 may be omitted. In each of the above embodiments, the peripheral posts 63 are provided at the corners of the corresponding area 526 when viewed from the second substrate 53 side relative to the first substrates 52, 52E, and are arranged at equal intervals along the periphery of the corresponding area 526. However, the number and arrangement of the peripheral posts 63 are not limited to the above and may be changed as appropriate.

[0082] In each of the above embodiments, the outer columns 64 are arranged at equal intervals within the accommodation chamber 54, excluding the corresponding region 526. However, this is not limited to this, and the outer columns 64 may be arranged randomly within the accommodation chamber 54, excluding the corresponding region 526. In other words, the arrangement and number of the outer columns 64 are not limited to those described above.

[0083] In each of the above embodiments, the first inner surface 525 is provided with either the first capillary force structure 56A or 56B, the second inner surface 534 is provided with either the second capillary force structure 57A or 57B, and the outer peripheral surfaces of the pillars 6A and 6D are provided with the third capillary force structure 58. However, this is not limiting, and at least one of the first capillary force structures 56A and 56B, the second capillary force structures 57A and 57B, and the third capillary force structure 58 may be omitted. The first capillary force structures 56A and 56B do not have to be provided on the entire first inner surface 525, but may be provided on a part of the first inner surface 525. Similarly, the second capillary force structures 57A and 57B do not have to be provided on the entire second inner surface 534, but may be provided on a part of the second inner surface 534. Furthermore, the third capillary force structure 58 does not have to be provided on all of the plurality of pillars 6A, 6D, and may be provided only on the inner pillars 61, 65, for example.

[0084] In each of the above embodiments, the projector includes three light modulation elements 243R, 243G, and 243B. However, the present disclosure is not limited to this and can also be applied to a projector including two or less light modulation elements, or four or more light modulation elements.

[0085] In each of the above embodiments, the light modulation element 243 is a transmissive liquid crystal panel having a light incident surface and a light exit surface that are different from each other. However, the light modulation element 243 is not limited to this, and may be a reflective liquid crystal panel having a light incident surface and a light exit surface that are the same. Furthermore, the light modulation element 243 may be a light modulation element other than a liquid crystal, such as a device using a micromirror, for example, a DMD (Digital Micromirror Device), as long as it is a light modulation element that can modulate an incident light beam to form an image according to image information.

[0086] In the above embodiments, the vapor chambers 5A, 5B, 5C, 5D, and 5E constitute the wavelength conversion devices 4A, 4D, and 4E, and the heating element disposed in the arrangement area 523 of the vapor chambers 5A, 5B, 5C, 5D, and 5E is the phosphor 41. However, the present disclosure is not limited to this, and the heating element provided in the arrangement area of ​​the vapor chamber is not limited to the phosphor, and may be other heating elements such as a solid-state light-emitting element and a semiconductor element.

[0087] In the above embodiments, the projector 1 including the light source 31, the image forming device 24, and the projection optical device 26 has been exemplified as an electronic device including the cooling devices CDA and CDE. However, the electronic device including the vapor chamber of the present disclosure is not limited to this, and may be other electronic devices such as an information processing device and a light source device.

[0088] Summary of this disclosure A summary of this disclosure is provided below. [Appendix 1] a first substrate having thermal conductivity; a second substrate facing the first substrate and having thermal conductivity; an accommodation chamber having an accommodation space formed by joining a peripheral portion of the first substrate and a peripheral portion of the second substrate; a working medium accommodated in the accommodation chamber and capable of changing between a gas phase and a liquid phase due to heat; a plurality of pillars disposed in the accommodation chamber between the inner surface of the first substrate and the inner surface of the second substrate; The first substrate is an arrangement area located on an outer surface of the first substrate, in which a heating element is arranged; a corresponding area located on the inner surface of the first substrate and corresponding to the placement area; The plurality of pillars At least one inner post disposed in the corresponding region; a plurality of outer pillars disposed outside the corresponding region; The number of the inner columns per unit area in the corresponding region is greater than the number of the columns per unit area in the entire storage chamber; A vapor chamber characterized by:

[0089] With this configuration, the number of inner columns per unit area in the corresponding region is greater than the number of columns per unit area in the entire containment chamber. This increases the pressure resistance of the corresponding region against expansion of the vapor chamber. This prevents the vapor chamber from expanding even when an external thermal load is applied to the placement region. On the other hand, since the number of outer columns per unit area arranged outside the corresponding area is smaller than the number of inner columns per unit area arranged in the corresponding area, it is possible to easily diffuse the working fluid that has changed from a liquid phase to a gas phase due to heat transferred from the heating element in the corresponding area located on the inner surface of the first substrate outside the corresponding area. Therefore, the expansion of the vapor chamber can be suppressed while maintaining the diffusibility of the working medium in the vapor chamber.

[0090] [Appendix 2] In the vapor chamber according to Appendix 1, a cross-sectional area of ​​the at least one inner column along the inner surface of the first substrate at a portion of the at least one inner column on the first substrate side is smaller than a cross-sectional area of ​​each of the outer columns along the inner surface of the first substrate at a portion of the at least one inner column on the first substrate side; A vapor chamber characterized by: With this configuration, the area of ​​the corresponding region where the liquid-phase working fluid is transformed into the gas-phase working fluid by the heat transferred from the heating element can be prevented from being reduced by the inner column, thereby preventing the heat transfer from the inner surface of the first substrate to the liquid-phase working fluid from being hindered, and therefore preventing a decrease in the efficiency of heat transfer from the heating element to the liquid-phase working fluid.

[0091] [Appendix 3] In the vapor chamber according to Appendix 1 or Appendix 2, a thickness dimension of the first substrate in the placement region is smaller than a thickness dimension of the first substrate around the placement region; A vapor chamber characterized by: This configuration improves the efficiency of heat transfer from the heating element to the inner surface of the first substrate, and ultimately from the heating element to the liquid-phase working fluid, thereby improving the efficiency of cooling the heating element.

[0092] [Appendix 4] In the vapor chamber according to any one of Supplementary Note 1 to Supplementary Note 3, the at least one interior pillar includes an area pillar; The entire intra-area pillar is disposed within the corresponding area when viewed from the second substrate side relative to the first substrate. A vapor chamber characterized by: With this configuration, the inner-region pillars, which are entirely disposed within the corresponding region, can suppress expansion of the portion of the vapor chamber corresponding to the region in which they are disposed, thereby increasing the pressure resistance of the vapor chamber.

[0093] [Appendix 5] Attachment 1 to Attachment 4, the vapor chamber of any one of the following: the at least one inner post includes a peripheral post disposed on a periphery of the corresponding region; The peripheral pillars are arranged across the interior and exterior of the corresponding area. A vapor chamber characterized by: With this configuration, the peripheral pillars can prevent the peripheral portion of the placement area from expanding due to heat acting on the placement area from the outside, thereby increasing the pressure resistance of the vapor chamber.

[0094] [Appendix 6] In the vapor chamber described in Appendix 5, The peripheral pillars are provided at equal intervals on the periphery of the corresponding area, Among the plurality of outer columns, the plurality of outer columns arranged around the at least one inner column are arranged at equal intervals. A vapor chamber characterized by: With this configuration, the peripheral posts are provided at equal intervals around the periphery of the corresponding area, which effectively suppresses expansion of the portion of the vapor chamber corresponding to the placement area, thereby reducing the flatness of the vapor chamber. Furthermore, since the multiple outer columns arranged around the inner column are arranged at equal intervals, the multiple outer columns can be prevented from hindering the diffusion of the working medium vaporized in the corresponding region outside the corresponding region.

[0095] [Appendix 7] 7. The vapor chamber according to claim 1, a first capillary force structure disposed on an inner surface of the first substrate inside the accommodation chamber and holding the working medium in a liquid phase; A vapor chamber characterized by: This configuration makes it easier to supply the liquid-phase working medium to the corresponding region to which heat from the heating element is transferred, thereby improving the efficiency of heat transfer from the heating element to the working medium and the cooling efficiency of the heating element.

[0096] [Appendix 8] In the vapor chamber according to Appendix 7, the at least one inner post is bonded to the inner surface of the first substrate, avoiding the first capillary force structure; A vapor chamber characterized by: With this configuration, the inner pillar can be directly bonded to the inner surface of the first substrate, thereby increasing the bonding strength between the inner pillar and the inner surface of the first substrate and further increasing the pressure resistance strength of the vapor chamber.

[0097] [Appendix 9] In the vapor chamber according to Appendix 7, the at least one inner post is bonded to the inner surface of the first substrate via the first capillary force structure; A vapor chamber characterized by: With this configuration, the area of ​​the first capillary force structure is prevented from being reduced by the inner pillar, and therefore the retention and transport power of the first capillary force structure for the liquid working fluid is prevented from being reduced. Therefore, the liquid working fluid can be efficiently transported to the corresponding region, thereby increasing the efficiency of heat transfer from the heating element to the liquid working fluid.

[0098] [Appendix 10] In the vapor chamber according to Appendix 7, a second capillary force structure disposed on an inner surface of the second substrate inside the accommodation chamber and holding the working medium in a liquid phase; one end of the at least one inner post is bonded to the inner surface of the first substrate, avoiding the first capillary force structure; the other end of the at least one inner post is bonded to the inner surface of the second substrate via the second capillary force structure; A vapor chamber characterized by: According to this configuration, as in the above, one end of the inner post can be directly bonded to the inner surface of the first substrate, thereby increasing the bonding strength between the inner post and the inner surface of the first substrate. Furthermore, since the inner pillars can prevent the area of ​​the second capillary force structure from being reduced, the retention and transport power of the liquid phase working medium by the second capillary force structure can be prevented from being reduced. Therefore, the pressure resistance strength of the vapor chamber can be further increased, and the liquid phase working medium can be efficiently transported toward the corresponding area, thereby improving the heat transfer efficiency from the heating element to the liquid phase working medium.

[0099] [Appendix 11] 11. The vapor chamber according to claim 10, a third capillary force structure provided on the outer surface of the inner column and connecting the first capillary force structure and the second capillary force structure; A vapor chamber characterized by: With this configuration, the liquid-phase working medium transported by the second capillary force structure can be supplied to the first capillary force structure via the third capillary force structure, which in turn makes it easier to supply the liquid-phase working medium to the corresponding region. This further improves the efficiency of heat transfer from the heating element to the liquid-phase working medium, thereby improving the cooling efficiency of the heating element.

[0100] [Appendix 12] A vapor chamber according to any one of claims 1 to 11; The heating element is joined to the placement area. A cooling device characterized by: With this configuration, a cooling device can be constructed that can cool the heat generating element while suppressing expansion of the vapor chamber.

[0101] [Appendix 13] 13. The cooling device according to claim 12, An electronic device characterized by: According to this configuration, it is possible to achieve the same effect as the cooling device described above, and to configure an electronic device that can operate stably.

[0102] [Appendix 14] 13. A cooling device according to claim 12, the heating element is a phosphor that converts the wavelength of incident light and emits fluorescent light, The phosphor is bonded to the placement region via a thermally conductive bonding material. A wavelength conversion device characterized by: According to this configuration, the phosphor can be cooled stably, and therefore a wavelength conversion device capable of stably emitting fluorescent light can be configured.

[0103] [Appendix 15] A light source and 15. The wavelength conversion device according to claim 14, wherein light from the light source is incident as excitation light; an image forming device that forms image light from light including the fluorescent light emitted from the phosphor; a projection optical device that projects the image light, A projector characterized by: According to this configuration, it is possible to achieve the same effect as the wavelength conversion device described above, and to configure a projector that can operate stably. [Explanation of symbols]

[0104] 1...Projector (electronic device), 24...Image forming device, 26...Projection optical device, 3...Light source device, 31...Light source, 4A, 4D, 4E...Wavelength conversion device, 41...Phosphor, 42...Bonding material, 43...Heat dissipation member, 5A, 5B, 5C, 5D, 5E...Vapor chamber, 51A...First outer surface, 51B...Second outer surface, 52, 52E...First substrate, 521...First surface, 522...Second surface, 523...Arrangement area, 524...First peripheral portion, 525...First inner surface, 526...Corresponding area, 527...Arrangement recess, 5 271...bottom surface, 53...second substrate, 531...first surface, 532...second surface, 533...second peripheral portion, 534...second inner surface, 54...accommodation chamber, 54S...accommodation space, 55A, 55B, 55C...capillary force structure, 56A, 56B...first capillary force structure, 56A1...hole portion, 57A, 57B...second capillary force structure, 57A1...hole portion, 58...third capillary force structure, 6A, 6D...pillars, 61, 65...inner pillars, 62, 66...region inner pillars, 63, 67...peripheral pillars, 64...outer pillars, CDA, CDE...cooling device.

Claims

1. a first substrate having thermal conductivity; a second substrate facing the first substrate and having thermal conductivity; an accommodation chamber having an accommodation space formed by joining a peripheral portion of the first substrate and a peripheral portion of the second substrate; a working medium accommodated in the accommodation chamber and capable of changing between a gas phase and a liquid phase due to heat; a plurality of pillars disposed in the accommodation chamber between an inner surface of the first substrate and an inner surface of the second substrate; The first substrate is an arrangement area located on an outer surface of the first substrate, in which a heating element is arranged; a corresponding area located on the inner surface of the first substrate and corresponding to the placement area; The plurality of pillars At least one inner post disposed in the corresponding region; a plurality of outer pillars disposed outside the corresponding region; The number of the inner columns per unit area in the corresponding region is greater than the number of the columns per unit area in the entire storage chamber; A vapor chamber characterized by:

2. The vapor chamber according to claim 1, a cross-sectional area of ​​the at least one inner column along the inner surface of the first substrate at a portion of the at least one inner column on the first substrate side is smaller than a cross-sectional area of ​​each of the outer columns along the inner surface of the first substrate at a portion of the at least one inner column on the first substrate side; A vapor chamber characterized by:

3. The vapor chamber according to claim 1 or 2, a thickness dimension of the first substrate in the placement region is smaller than a thickness dimension of the first substrate around the placement region; A vapor chamber characterized by:

4. The vapor chamber according to claim 1 or 2, the at least one interior pillar comprises an intra-area pillar; The entire intra-area pillar is disposed within the corresponding area when viewed from the second substrate side relative to the first substrate. A vapor chamber characterized by:

5. The vapor chamber according to claim 1 or 2, the at least one inner post includes a peripheral post disposed on a periphery of the corresponding region; The peripheral pillars are arranged across the interior and exterior of the corresponding area. A vapor chamber characterized by:

6. The vapor chamber according to claim 5, The peripheral pillars are provided at equal intervals on the periphery of the corresponding area, Among the plurality of outer columns, the plurality of outer columns arranged around the at least one inner column are arranged at equal intervals. A vapor chamber characterized by:

7. The vapor chamber according to claim 1 or 2, a first capillary force structure disposed on an inner surface of the first substrate inside the accommodation chamber and configured to hold the working medium in a liquid phase; A vapor chamber characterized by:

8. The vapor chamber according to claim 7, the at least one inner post is bonded to the inner surface of the first substrate, avoiding the first capillary force structure; A vapor chamber characterized by:

9. The vapor chamber according to claim 7, the at least one inner post is bonded to the inner surface of the first substrate via the first capillary force structure; A vapor chamber characterized by:

10. The vapor chamber according to claim 7, a second capillary force structure disposed on an inner surface of the second substrate inside the accommodation chamber and holding the working medium in a liquid phase; one end of the at least one inner post is bonded to the inner surface of the first substrate, avoiding the first capillary force structure; the other end of the at least one inner post is bonded to the inner surface of the second substrate via the second capillary force structure; A vapor chamber characterized by:

11. The vapor chamber according to claim 10, a third capillary force structure provided on an outer surface of the inner column and connecting the first capillary force structure and the second capillary force structure; A vapor chamber characterized by:

12. The vapor chamber according to claim 1 or 2; The heating element is joined to the placement area. A cooling device characterized by:

13. A cooling device according to claim 12, An electronic device characterized by:

14. A cooling device according to claim 12, the heating element is a phosphor that converts the wavelength of incident light and emits fluorescent light, The phosphor is bonded to the placement region via a thermally conductive bonding material. A wavelength conversion device characterized by:

15. A light source and The wavelength conversion device according to claim 14 , wherein the light from the light source is incident as excitation light; an image forming device that forms image light from light including the fluorescent light emitted from the phosphor; a projection optical device that projects the image light, A projector characterized by:

Images